This application relates generally to an internal combustion engine. More specifically, this application relates to a rotary internal combustion engine.
Internal combustion engines provide a mechanism for generating energy through the combustion of a fuel with an oxidizer, with typical fuels including diesel, gasoline, petroleum gas, and propane, and typical oxidizers including air. A number of different designs for internal combustion engines are known, including reciprocating engines in which pistons move within cylinders to convert pressure into rotational motion. Examples of reciprocating engines particularly include stroke engines, with designs that implement two-stroke cycles, four-stroke cycles, and six-stroke cycles, although there are other designs also.
Other structures for internal combustion engines avoid the use of pistons, such as by using rotors to effect the conversion of pressure into rotational motion instead of reciprocating pistons.
Both reciprocating engines and rotary engines are examples of engines that operate with intermittent combustion. Other designs use the same general principle of converting pressure into rotational motion, but are configured so that the combustion is continuous.
There are a number of sources of inefficiency in various engine designs, and some designs are more susceptible to operational failures. For example, in some rotary designs, contact between the rotary vanes and stationary parts of the engine reduces the lifetime of the engine because of progressive damage arising from friction. Other designs have constant-volume combustion chambers, limiting the ability for combustion gases to expand under pressure. In most such engines, the gases under pressure have little leverage when acting on the rotary part so that the efficiency can be low.
Some engines that function as conventional two- or four-stroke engines provide insufficient time for complete fuel burning or lack ways to cool, resulting in limited efficiency. Other disadvantages that are known with convention two- or four-stroke engines include variations in leverage, with relatively little leverage being provided at the beginning of the power stroke so that power may be lost at the end of the power stroke. In addition, the exhaust valve is typically opened when the cylinders are still under pressure, contributing to power loss, particularly at high revolution speeds. These types of engines tend to have a large number of moving parts, which can be heavy so that energy is lost in accelerating those parts. There may also be significant losses due to friction between the moving parts.